title: Synthesis of azetidines and pyrrolidines via iodocyclisation of homoallyl amines and exploration of activity in a zebrafish embryo assay.
abstract: Room temperature iodocyclisation of homoallylamines stereoselectively delivers functionalised 2-(iodomethyl)azetidine derivatives in high yield. Increasing reaction temperature from 20 °C to 50 °C switches the reaction outcome to realise the stereoselective formation of functionalised 3-iodopyrrolidine derivatives. It was shown that these pyrrolidines are formed via thermal isomerisation of the aforementioned azetidines. Primary and secondary amines could be reacted with iodomethyl azetidine derivatives to deliver stable methylamino azetidine derivatives. With subtle changes to the reaction sequences homoallyl amines could be stereoselectively converted to either cis- or trans-substituted 3-amino pyrrolidine derivatives at will. The stereochemical divergent synthesis of cis and trans substituted pyrrolidines supports an ion part, aziridinium, isomerisation pathway for azetidine to pyrrolidine isomerisation. Six azetidine derivatives were probed in a zebrafish embryo developmental assay to detect potential biological effects through the analysis of morphology and motility behaviour phenotypes. The range of effects across the probed molecules demonstrates the suitability of this assay for screening azetidine derivatives. One of the probed molecules, rac-(((cis)-1-benzyl-4-phenylazetidin-2-yl)methyl)piperidine, exhibited particularly interesting effects in the developmental assay presenting with hypopigmentation and reduced circulation amongst others. This shows that the zebrafish embryo provides a fast, sensitive and effective way to screen new compounds and in the future in combination with existing in vivo and in vitro assays it will become an integral part in drug discovery and development.
authors.affiliation: School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
authors.forename: Antonio
authors.initials: A
authors.lastname: Feula
authors.forename: Sundeep S
authors.initials: SS
authors.lastname: Dhillon
authors.forename: Rama
authors.initials: R
authors.lastname: Byravan
authors.forename: Mandeep
authors.initials: M
authors.lastname: Sangha
authors.forename: Ronald
authors.initials: R
authors.lastname: Ebanks
authors.forename: Mariwan A Hama
authors.initials: MA
authors.lastname: Salih
authors.forename: Neil
authors.initials: N
authors.lastname: Spencer
authors.forename: Louise
authors.initials: L
authors.lastname: Male
authors.forename: Istvan
authors.initials: I
authors.lastname: Magyary
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Deng
authors.forename: Ferenc
authors.initials: F
authors.lastname: Müller
authors.forename: John S
authors.initials: JS
authors.lastname: Fossey
mesh_terms: D000818:Animals; D001384:Azetidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D001681:Biological Assay; D003500:Cyclization; D004625:Embryo, Nonmammalian / Q000187:drug effects; D007455:Iodine / Q000737:chemistry*; D010858:Pigmentation / Q000187:drug effects; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D015027:Zebrafish / Q000002:abnormalities / Q000196:embryology*
chemical_list: D001384:Azetidines; D011759:Pyrrolidines; D007455:Iodine